The present invention relates to a digital recording and reproduction apparatus for video signals and audio signals in the TV broadcasting, or more in particular to a time shift function.
A conventional technique for recording/reproducing the TV broadcast program is a VTR. The tape medium is considered as an inexpensive medium for recording video signals and audio signals. Nevertheless, the tape medium is not suitable for random access for its structure.
For reproducing the program recorded in the VTR, the tape is required to be rewound to the head of the program. Thus, it is difficult to reproduce the video information already recorded, while at the same time recording a program. The program which the user has started to record using a timer or the like cannot be viewed from the head of the program before the program is completely recorded to the last.
With the optical disk, which is superior to the tape in random accessibility, on the other hand, JP-A-6-290538 discloses a method using a CLV (constant linear velocity) scheme most suitable in terms of recording density for recording, while a CAV (constant angular velocity) scheme superior in accessibility is employed for reproduction. In a system for repeating the recording and reproduction alternately, however, the relation of the target rotational speed between the two processes has not been taken into consideration.
JP-A-11-232844 discloses performing recording and reproduction for each track alternately. However, it does not concretely teach any rotational speed control in the recording and reproduction.
Further, JP-A-7-111629 describes a technique for realizing the time shift using a disk-like recording medium. This technique, however, presupposes the use of two pickups and fails to refer to a method of controlling the rotation.